SAN FRANCISCO — Maybe your old truck isn’t responsible for destroying the planet after all. New climate change scenarios quantify the idea that oil is only a small component of the total global warming problem - the real problem is coal. If the world replaced all of its oil usage with carbon-neutral energy sources, ecologist Kenneth Caldeira of Stanford University calculated that it would only buy us about 10 years before coal emissions warmed the planet to what many scientists consider dangerous levels. ‘There’s an order of magnitude more coal than oil. So, whether there is a little more oil or a little less oil will change the details in, say, when we reach two degrees warming, but it doesn’t change the overall picture,’ Caldeira said Wednesday at the American Geophysical Union annual meeting. Many of the efforts to ‘green’ our world’s infrastructure have focused on the importance of changing the world’s transportation systems. Indeed, one of the images of environmental destruction is the car-choked freeways of Los Angeles - and hybrid vehicles like the Toyota Prius have become a badge of environmental pride. But as the latest projections show, when it comes to global […]